Semiconducting frameworks possessing porous structure are promising platforms for the detection of hazardous gas molecules. In this study, we propose a facile route to fabricate millimeter-scale, three-dimensional semiconducting SWCNT (s-SWCNT) aerogels and demonstrate deactivation of the co-existing metallic SWCNT (m-SWCNT) network via electrical breakdown process. In particular, the on-off ratio of the modulated semiconducting aerogel after the electrical breakdown process was 205, which is an increase of 18.9 times over that before the process. The modulated semiconducting SWCNT aerogels with a large specific surface area (∼1270 m2 g-1) demonstrated their applicability for highly sensitive ppb-level ozone detection. The modulated semiconducting networks led to a 1310 % increase in the magnitude of response to 30-ppb ozone gas injection compared with that of pristine SWCNT aerogels. Furthermore, the prepared aerogels could detect 3 ppb of ozone within 40 s and retain stable reversible ozone detection for 200 cyclic operations over 100 h. Thus, the proposed semiconducting SWCNT aerogels are a promising candidate for highly sensitive environmental gas sensors.

中文翻译：

---

用于高灵敏度臭氧检测的三维毫米级半导体SWCNT气凝胶。

具有多孔结构的半导体框架是用于检测有害气体分子的有前途的平台。在这项研究中，我们提出了一条制造毫米级，三维半导体SWCNT（s-SWCNT）气凝胶的简便途径，并证明了通过电击穿过程使共存的金属SWCNT（m-SWCNT）网络失活。特别地，在电击穿过程之后，调制半导体气凝胶的开-关比是205，比该过程之前增加了18.9倍。具有大比表面积（〜1270 m2 g-1）的调制半导体SWCNT气凝胶证明了其在高灵敏度ppb级臭氧检测中的适用性。与原始SWCNT气凝胶相比，调制的半导体网络导致对30 ppb臭氧气体注入的响应幅度提高了1310％。此外，制备的气凝胶可以在40 s内检测到3 ppb的臭氧，并在100 h内进行200次循环操作后仍保持稳定的可逆臭氧检测。因此，提出的半导体SWCNT气凝胶是高灵敏度环境气体传感器的有希望的候选者。